Cutenews 2.0.3 Size Upload

Hello everyone,

When I upload a file (in this case a pdf) with a size greater than 3Mb by media manager not upload the file, just return to the dashboard.
I've been upload files 1Mb or 2Mb but not 3Mb or more.
Maybe there is a file in which it is to set the upload size.

If anyone can tell me how to fix this problem.

Thanks and sorry for my english.